CN111904446A - Mammary gland imaging system and imaging method thereof - Google Patents

Abstract

The invention provides a breast imaging system and an imaging method thereof. The breast imaging system includes an X-ray source, a photon counting detector and a processor; the X-ray source is used to emit X-rays from different angles, and the photon counting detector and the processor are electrically connected to the X-ray source. Sexual connection, the photon counting detector is used for collecting a plurality of projection images after the X-rays emitted by the X-ray source from different angles pass through the mammary gland, and the processor is used for respectively enhancing and enhancing each projection image in the plurality of projection images After the multiple projection images are reconstructed. The breast imaging system provided by the present invention adopts a photon counting detector to collect multiple projection images of X-rays emitted by an X-ray source from different angles after passing through the breast, and can simultaneously obtain a high-energy image and a low-energy image in one exposure process , which avoids the need for two exposures in the existing functional imaging technology to significantly increase the radiation dose and generate motion artifacts, and improves the imaging quality while reducing the radiation dose.

Description

Breast imaging system and imaging method thereof

technical field

The invention relates to the technical field of X-ray imaging, in particular to a breast imaging system and an imaging method thereof.

Background technique

Breast cancer is an important disease that seriously threatens women's health worldwide, ranking first in the incidence of female malignant tumors. Early detection and early treatment can significantly improve the survival of breast cancer patients, and accurate diagnosis is an important part of improving the survival rate of breast cancer patients. At present, mammography is the preferred method for breast cancer screening and diagnosis. It can detect early-stage breast cancers with negative clinical palpation, especially breast cancers characterized by calcification.

Traditional mammography is a morphological technique that presents the tissue structure of the breast rather than physiology. Although abnormal findings can already be detected during screening, additional functional imaging techniques can present atypical findings in the diagnostic workup of recalled women. Physiological processes that offer significant diagnostic advantages. The most common functional imaging technique is contrast-enhanced breast X-ray imaging. However, contrast-enhanced breast X-ray imaging requires two exposures, which significantly increases the radiation dose and produces motion artifacts, which increase the image quality. Quasi-difficulty.

SUMMARY OF THE INVENTION

In order to solve the deficiencies of the prior art, the present invention provides a breast imaging system and an imaging method thereof, which can reduce the radiation dose and improve the imaging quality.

The specific technical solution proposed by the present invention is to provide a breast imaging system, which includes an X-ray source, a photon counting detector and a processor; the X-ray source is used for emitting X-rays from different angles, and the The photon counting detector is electrically connected to the processor, and the photon counting detector is used for collecting a plurality of projection images of the X-rays emitted by the X-ray source from different angles after passing through the breast, and the processor is used for respectively Each of the plurality of projection images is enhanced and the enhanced plurality of projection images are reconstructed.

Further, the photon counting detector includes a control circuit, a circuit board and a plurality of detection units arranged on the circuit board, the control circuit is electrically connected to the processor, and the circuit board is connected to the control circuit. The circuit is electrically connected, and the plurality of detection units are arranged in an array and are all electrically connected to the circuit board.

Further, each of the detection units includes a semiconductor layer, an electrode and a chip layer, the electrode is used to electrically connect the semiconductor layer and the chip layer, and the chip layer is electrically connected to the circuit board.

Further, the material of the semiconductor layer is cadmium telluride or cadmium zinc telluride.

Further, the breast imaging system further includes a frame, a compression plate and an adjustment unit, the compression plate is slidably connected on the frame, the photon counting detector is fixed on the frame, and the adjustment unit is For adjusting the distance between the compression plate and the photon counting detector, the breast is clamped by the compression plate and the photon counting detector.

Further, the X-ray source includes a plurality of X-ray tubes, and the plurality of X-ray tubes are arranged in an arc, and the breast imaging system further includes a control device, and the control device is used for triggering sequentially at different time periods. A plurality of the X-ray tubes are turned on to emit X-rays from different angles.

Further, the X-ray source is a cold cathode X-ray source, the breast imaging system further includes a first power supply, a second power supply and a third power supply, and the first power supply is used for the grid of the X-ray source A voltage is provided, the second voltage source is used to power the focusing electrode of the X-ray source, and the third power source is used to power the anode of the X-ray source.

Further, the tube current of the X-ray source is not less than 100 mA, the tube voltage of the X-ray source is 20-50 kV, and the focal diameter of the X-ray source is 0.1-0.3 mm.

The present invention also provides an imaging method for a breast imaging system as described above, the imaging method comprising:

X-ray sources emit X-rays from different angles;

The photon counting detector collects multiple projection images of the X-rays emitted by the X-ray source from different angles after passing through the mammary gland;

The processor enhances each of the plurality of projection images and reconstructs the enhanced projection images, respectively.

Further, the processor enhancing each of the plurality of projection images respectively and reconstructing the enhanced plurality of projection images specifically includes:

extracting a low-energy image corresponding to a photon whose photon energy is greater than a first energy threshold in each of the plurality of projection images;

extracting a high-energy image corresponding to a photon whose photon energy is greater than a second energy threshold in each of the plurality of projection images, where the second energy threshold is greater than the first energy threshold;

performing subtraction processing on the low-energy image and the high-energy image to obtain an enhanced image corresponding to each of the plurality of projection images;

reconstructing an enhanced image corresponding to each of the plurality of projection images.

The breast imaging system provided by the present invention adopts the photon counting detector to collect multiple projection images of the X-rays emitted by the X-ray source from different angles after passing through the breast. Since the photon counting detector can simultaneously detect high-energy photons and low-energy photons Photons are collected, so that high-energy images and low-energy images can be obtained simultaneously in a single exposure process, avoiding the need for two exposures in existing functional imaging techniques, which leads to significantly increased radiation dose and motion artifacts. The image quality is improved at the same time.

Description of drawings

The technical solutions and other beneficial effects of the present invention will be apparent through the detailed description of the specific embodiments of the present invention with reference to the accompanying drawings.

FIG. 1 is a schematic structural diagram of a breast imaging system in Embodiment 1 of the present application;

2 is a schematic structural diagram of a photon counting detector in Embodiment 1 of the present application;

3 is a schematic diagram of the circuit structure of the adjustment unit in Embodiment 1 of the present application;

4 is a schematic flowchart of the imaging method in Embodiment 1 of the present application;

FIG. 5 is a schematic structural diagram of an X-ray source in Embodiment 2 of the present application.

Detailed ways

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the specific embodiments set forth herein. Rather, these embodiments are provided to explain the principles of the invention and its practical application, to thereby enable others skilled in the art to understand the invention for various embodiments and with various modifications as are suited to the particular intended use. Throughout the drawings, the same reference numbers will be used to refer to the same elements.

The breast imaging system provided by the present application includes an X-ray source, a photon counting detector and a processor. The X-ray source is used to emit X-rays from different angles, the photon counting detector is electrically connected to the processor, and the photon counting detector is used to collect multiple projection images of the X-rays emitted by the X-ray source from different angles after passing through the mammary gland, The processor is configured to enhance each of the plurality of projection images and reconstruct the enhanced plurality of images, respectively.

The breast imaging system provided by the present application collects multiple projection images of X-rays emitted by an X-ray source from different angles after passing through the breast through a photon counting detector. Since the photon counting detector can simultaneously detect high-energy photons and low-energy photons Photons are collected, so that high-energy images and low-energy images can be obtained simultaneously in a single exposure process, avoiding the need for two exposures in existing functional imaging techniques, which leads to significantly increased radiation dose and motion artifacts. The image quality is improved at the same time.

The breast imaging system and its imaging method in the present application will be described in detail below through specific embodiments and in conjunction with the accompanying drawings.

Example 1

Referring to FIG. 1 , the breast imaging system in this embodiment includes an X-ray source 1 , a spiral arm 2 , a photon counting detector 3 and a processor 4 . The X-ray source 1 in this embodiment is a single-focus plate-type ray source, that is, the X-ray source 1 only includes an X-ray tube, and the X-ray tube is fixed on the swivel arm 2 , and the swivel arm 2 is used to drive the X-ray source 1 to rotate , the X-ray source 1 emits X-rays from different angles when it rotates. The photon counting detector 3 is electrically connected with the processor 4, and the photon counting detector 3 is used for collecting a plurality of projection images of the X-rays emitted by the X-ray source 1 from different angles after passing through the breast 5, and the processor 4 is used for respectively Each of the plurality of projection images is enhanced and the enhanced plurality of projection images are reconstructed.

Specifically, the rotating arm 2 is connected with a driving motor (not shown in the figure), and the rotation of the rotating arm 2 is driven by the driving motor, so as to realize precise control of the rotation angle. The breast 5 is located between the X-ray source 1 and the photon counting detector 3, and the photon counting detector 3 is a flat plate type. During the imaging process, the projection image of the X-ray emitted by the X-ray source 1 after passing through the breast 5 is detected by the photon counting The photon counting detector 3 then sends the collected projection images to the processor 4, wherein the processor 4 may be an image processor such as a computer or a single-chip microcomputer.

Referring to FIG. 2 , the photon counting detector 3 in this embodiment includes a control circuit 31 , a circuit board 32 and a plurality of detection units 33 arranged on the circuit board 32 . The control circuit 31 is electrically connected to the processor 4 , and the circuit board 32 Electrically connected to the control circuit 31 , a plurality of detection units 33 are arranged in an array and are all electrically connected to the circuit board 32 . The number of detection units 33 can be determined according to the actual detection resolution, for example, higher detection resolution can be obtained by setting more detection units 33 .

Specifically, each detection unit 33 includes a semiconductor layer 331 , an electrode 332 and a chip layer 333 . The electrode 332 is used to electrically connect the semiconductor layer 331 and the chip layer 333 , and the chip layer 333 is electrically connected to the circuit board 32 . The semiconductor layer 331 is used to receive the optical signal after the X-ray emitted by the X-ray source 1 passes through the breast 5 and convert the optical signal into an electrical signal, and the electrode 332 is used to send the electrical signal generated by the semiconductor layer 331 to the chip layer 333. The layer 333 is used for processing the electrical signal, for example, converting the electrical signal into a digital signal and counting photons corresponding to the electrical signal according to the magnitude relationship between the amplitude of the electrical signal and a predetermined threshold.

The output end of the chip layer 333 is electrically connected to the circuit board 32 through metal leads, and the circuit board 32 sends the signal output by the chip layer 333 to the control circuit 31 , and the control circuit 31 processes the signal output by the chip layer 333 and sends it to the processor 4.

Preferably, the material of the semiconductor layer is cadmium telluride or cadmium zinc telluride.

The breast imaging system in this embodiment further includes a frame 6 , a compression plate 7 and an adjustment unit 8 . The compression plate 7 is slidably connected to the frame 6 , that is, the compression plate 7 can slide up and down relative to the frame 6 . The photon counting detector 3 is fixed on the frame 6 and is located below the compression plate 7 . The adjustment unit 8 is connected with the compression plate 7, which is used to adjust the distance between the compression plate 7 and the photon counting detector 3, the breast 5 is sandwiched between the compression plate 7 and the photon counting detector 3, and the compression is adjusted by the adjustment unit 8 The distance between the plate 7 and the photon counting detector adjusts the pressure applied to the mammary gland 5 .

3 , specifically, the adjustment unit 8 includes a thickness calculation circuit 81 , a pressure feedback circuit 82 and a control circuit 83 . The thickness calculation circuit 81 is used to calculate the thickness of the breast 5 . The thickness calculation circuit 81 in this embodiment includes a distance sensor provided in the compression plate 7 , and the thickness of the breast is obtained through the distance sensor. The pressure feedback circuit 82 is used to obtain the pressure applied to the breast 5 , and the control circuit 83 is used to control the movement of the compression plate 7 according to the thickness of the breast and the magnitude of the pressure applied to the breast 5 .

Preferably, the swivel arm 2 is a C-shaped arm, the swivel arm 2 is rotatably connected to the gantry 6, the swivel arm 2 can rotate around the gantry 6, and the X-ray source 1 and the adjustment unit 8 are located at two ends of the swivel arm 2 respectively. , wherein the X-ray source 1 is fixed on the top of the arm 2 , and the adjustment unit 8 is arranged at the bottom of the arm 2 .

The X-ray source 1 is a cold cathode ray source or a hot cathode ray source. In this embodiment, the X-ray source 1 is a cold cathode X-ray source. The breast imaging system further includes a first power source (not shown) and a second power source (not shown in the figure). Not shown) and a third power supply (not shown), the first power supply is used to provide voltage for the grid of the X-ray source 1, the second voltage source is used to supply power to the focusing electrode of the X-ray source 1, and the third power supply is used for The anode of the X-ray source is powered.

Preferably, the X-ray source 1 in this embodiment is a carbon nano-X light source, the target material of the X-ray source 1 is a molybdenum target or a tungsten target, the tube current of the X-ray source 1 is not less than 100 mA, and the tube current of the X-ray source 1 is not less than 100 mA. The voltage is 20-50kV, so that a spot with a diameter of 0.1-0.3mm can be obtained, and the spot size can meet the requirements of breast imaging, that is, the focal size of the X-ray source 1 is 0.1-0.3mm.

The breast imaging system in this embodiment further includes a display 9, and the display 9 is electrically connected to the processor 4, and is used for displaying the reconstructed image output by the processor 4.

Referring to FIG. 4 , this embodiment also provides an imaging method of the above-mentioned breast imaging system, and the imaging method includes the steps:

S1, the arm 2 rotates the X-ray source 1 to different angles, so that the X-ray source 1 emits X-rays from different angles;

S2. The photon counting detector 3 collects multiple projection images of the X-rays emitted by the X-ray source 1 from different angles after passing through the mammary gland;

S3. The processor 4 respectively enhances each of the multiple projection images and reconstructs the enhanced multiple projection images.

In step S1, the rotation angle of the arm 2 is controlled by a driving motor (not shown).

In step S3, the processor 4 enhances each of the multiple projection images respectively and reconstructs the enhanced multiple projection images specifically includes:

S31, extracting a low-energy image corresponding to a photon whose photon energy is greater than a first energy threshold in each of the plurality of projection images;

S32, extracting a high-energy image corresponding to a photon whose photon energy is greater than a second energy threshold in each of the plurality of projection images, wherein the second energy threshold is greater than the first energy threshold;

S33, perform subtraction processing on the low-energy image and the high-energy image to obtain an enhanced image corresponding to each of the multiple projection images;

S34. Reconstruct the enhanced image corresponding to each of the multiple projection images.

In steps S31-S32, since the photons of the X-rays are distributed in a certain energy range, that is, the X-rays include both low-energy photons and high-energy photons, the photon counting detector 3 can simultaneously detect the photons during one exposure process. High-energy photons and low-energy photons are collected, and then a low-energy image and a high-energy image corresponding to each projected image are obtained according to different energy thresholds. For example, the first energy threshold is 10, and the second energy threshold is 40 , then the photons with photon energy greater than 10 in each projected image are regarded as the photons of the low-energy image, so as to obtain a low-energy image according to these photons, and the photons with photon energy greater than 40 in each projected image are regarded as the photons of the high-energy image, thus High-energy images are obtained from these photons.

In step S33, subtraction processing is performed on the low-energy image and the high-energy image by the following formula:

I'=log(I ₁ )-A×log(I ₂ )

Among them, I ₁ represents a low-energy image, I ₂ represents a high-energy image, I' represents an image after subtraction processing, and A is a weighting coefficient.

The imaging method in this embodiment can simultaneously obtain a low-energy image and a high-energy image in a single exposure process, which avoids the need for two exposures in the existing functional imaging technology, resulting in a significant increase in radiation dose and motion artifacts. The radiation dose is improved at the same time as the imaging quality.

Embodiment 2

5 , the X-ray source 1 in this embodiment is a multi-focus arc-shaped ray source. Specifically, the X-ray source 1 includes a plurality of X-ray tubes, and the plurality of X-ray tubes are arranged in an arc shape. The breast imaging system in this embodiment further includes a control device (not shown in the figure), the control device is used to sequentially trigger the on/off of multiple X-ray tubes in different time periods, so as to realize switching between different X-ray tubes, The X-ray source 1 is made to emit X-rays from different angles.

Since the X-ray source 1 is a multi-focus arc-shaped ray source, the rotating arm 2 in this embodiment is fixedly connected to the gantry 6 . In the imaging method of the present embodiment, the X-ray source 1 only needs to emit X-rays from different angles by sequentially triggering the on/off of multiple X-ray tubes in different time periods by the control device.

The improvement of this embodiment over Embodiment 1 lies in that, since the X-ray source 1 does not need to be rotated in this embodiment, motion artifacts caused by the rotation of the X-ray source 1 can be avoided, and the imaging quality is further improved.

The above are only specific embodiments of the present application. It should be pointed out that for those skilled in the art, without departing from the principles of the present application, several improvements and modifications can also be made. It should be regarded as the protection scope of this application.

Claims (10)

1. A breast imaging system, characterized in that the breast imaging system comprises an X-ray source, a photon counting detector and a processor; the X-ray source is used to emit X-rays from different angles, and the photon counting detector Electrically connected with the processor, the photon counting detector is used for collecting multiple projection images of the X-rays emitted by the X-ray source from different angles after passing through the mammary gland, and the processor is used for respectively analyzing the multiple projection images. Each of the projection images is enhanced and the enhanced projection images are reconstructed. 2 . The breast imaging system according to claim 1 , wherein the photon counting detector comprises a control circuit, a circuit board and a plurality of detection units arranged on the circuit board, and the control circuit and the The processor is electrically connected, the circuit board is electrically connected to the control circuit, and the plurality of detection units are arranged in an array and are all electrically connected to the circuit board. 3. The breast imaging system according to claim 2, wherein each of the detection units comprises a semiconductor layer, an electrode and a chip layer, and the electrode is used to electrically connect the semiconductor layer and the chip layer, and the The chip layer is electrically connected to the circuit board. 4 . The breast imaging system according to claim 3 , wherein the semiconductor layer is made of cadmium telluride or cadmium zinc telluride. 5 . 5 . The breast imaging system according to claim 1 , wherein the breast imaging system further comprises a frame, a compression plate and an adjustment unit, and the compression plate is slidably connected to the frame. 6 . , the photon counting detector is fixed on the frame, and the adjustment unit is used to adjust the distance between the compression plate and the photon counting detector, and the photon counting detector passes through the compression plate and the photon counting detector. Clamp the breast. 6. The breast imaging system according to claim 5, wherein the X-ray source comprises a plurality of X-ray tubes, the plurality of X-ray tubes are arranged in an arc, and the breast imaging system further comprises a control device , the control device is used to sequentially trigger the opening of a plurality of the X-ray tubes in different time periods, so as to emit X-rays from different angles. 7. The breast imaging system according to claim 6, wherein the X-ray source is a cold cathode X-ray source, the breast imaging system further comprises a first power supply, a second power supply and a third power supply, the The first power supply is used for supplying voltage to the grid of the X-ray source, the second voltage source is used for supplying power to the focusing electrode of the X-ray source, and the third power supply is used for supplying power to the X-ray source. Anode powered. The breast imaging system according to claim 7, wherein the tube current of the X-ray source is not less than 100 mA, the tube voltage of the X-ray source is 20-50 kV, and the focal diameter of the X-ray source is 0.1 to 0.3 mm. 9 . The imaging method of a breast imaging system according to claim 1 , wherein the imaging method comprises: 10 . X-ray sources emit X-rays from different angles; The photon counting detector collects multiple projection images of the X-rays emitted by the X-ray source from different angles after passing through the mammary gland; The processor enhances each of the plurality of projection images and reconstructs the enhanced projection images, respectively. 10 . The imaging method according to claim 9 , wherein, the processor enhancing each of the plurality of projection images respectively and reconstructing the enhanced plurality of projection images specifically comprises: 10 . extracting a low-energy image corresponding to a photon whose photon energy is greater than a first energy threshold in each of the plurality of projection images; extracting a high-energy image corresponding to a photon whose photon energy is greater than a second energy threshold in each of the plurality of projection images, where the second energy threshold is greater than the first energy threshold; performing subtraction processing on the low-energy image and the high-energy image to obtain an enhanced image corresponding to each of the plurality of projection images; reconstructing an enhanced image corresponding to each of the plurality of projection images.

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